Every atom in the Universe is functioning in the way we perceive it, because of the Sathva, Rajas and Thamo gunas inherent in the universe. The same three Gunas are in the human being also.The entire Nature around us runs the way we see it, because of the changes constantly occurring in the three Gunas. But, the man with great pride (Ahankara) thinks, that he is the causative factor for every thing happening around him(v.27). We will deal with the three Gunas in detail separately.
In short, Sathva is the guna of the wise, Rajas is the guna of the Highly active and Thamas is the guna of the idle. Sathva guna gives joy, peace, compassion etc, Rajas gives anger,activity and fighting tendency while thamas gives hatred,jealousy, idleness etc. Our thinking and actions are most of the time the result of lack of balance in these 3 gunas in us. Once you understand the effect of the three gunas in you, instantly,you get the power to release yourself from their effect. Else, you will always be a slave to them.(v.28)
Since people (ignorant) are always subject to the effect of the three gunas, they can never think on their own. It is pointless to confuse them with intricate truths. The wise man must teach them in a easy way they can understand (v.29)
One must understand this and fight the battle of life, with no perturbation, leaving the karma ownership to the creator.This is the highest form of Karma. The karma yogi who leaves the Karma ownership (to the creator)and sails through the battle of life will get the same result that a Jnana Yogi (the wisest) gets. (v.30,31).
What is essential is, doing the Karma with great devotion to the work, without jealousy and other negative feelings. People who do not understand this great method of life go on criticizing this and spoil their own life.(v.32)
Actually, the nature in us through the three gunas prompts us to do and not do things. The five senses are always out-bound and they create our likes and dislikes. Through these likes and dislikes, the external world takes control over us. We need to bring the five senses back to our control.(v.33). This is a great statement. Our likes and dislikes pass on control over us - from ourselves to the objects / people outside us, on whom our likes and dislikes rest. When we know that - we will also know - why our likes and dislikes must be within our control, and how we can keep our life within our control.